As the remedial agent for the acute cerebral infarction, an antithrombotic agent (a thrombolytic agent, an anticoagulant, a platelet aggregation inhibitory agent) has been used hereinbefore. The remedy using such antithrombotic agent was given the priority to the treatment for the thrombus in blood vessel and the improvement of circulation. The known antithrombotic agent includes a tissue plasmigogen activator (hereinafter sometimes referred to as t-PA), a urokinase (UK), heparin, argatroban, ozagral sodium, aspirin and ticlopidine and the like.
However, if the antithrombotic agent is administered in large quantities or the administration of the antithrombotic agent is delayed, the conditions of the patient become worse by occurrence of the adverse effect of cerebral hemorrhage. Consequently, it cannot be said that there are few subjects to be solved.
Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), recently developed radical scavenger which was claimed in Japanese Patent Examined Publication (Kokoku) No. Hei. 4-35128 exhibits a free radical scavenging activity and an inhibiting activity against lipid peroxidation in cell membranes and the like. According to such activities, edaravone protects the nerve cell at the ischemic penumbra, and is able to keep the ischemic disorder to a minimum. The characteristics of edaravone includes no influence to the coagulation of blood and the aggregation of platelet and the like, and few hemorrhagic adverse effects.